consoledotdev / lamsubs

LaMetric HTTP endpoint for Mailchimp subscribers.

Mailchimp App for LaMetric

An HTTP endpoint for polling Mailchimp subscriber numbers for an LaMetric Time device. Designed to run on Azure Functions uusing a Custom Request Handler which receives HTTP requests and responds like a web app.

Methods

• get_subscribers: returns the latest stats from Mailchimp in JSON format as an LaMetric indicator app.

Development

Uses Rocket so requires Rust nightly. Set up a nightly override on the directory once cloned:

rustup override set nightly

Set environment variables (see below) with the relevant config then run:

cargo run

to start the web server. Issue requests to the endpoints e.g.:

curl -v http://localhost:3000/api/get_subscribers

Unit tests

cargo test

Testing with Azure Functions

Requirements:

• Azure Functions Core Tools

# Create the local.settings.json file which will set the environment variables
# Only required on a fresh clone when the file doesn't exist
func azure functionapp fetch-app-settings lamsubs
func start

Trigger HTTP function

curl -v http://localhost:7071/api/get_subscribers

Environment variables

• LAMSUBS_MAILCHIMP_APIKEY: Mailchimp API key.
• LAMSUBS_MAILCHIMP_LIST_ID: Mailchimp list ID string.
• LAMSUBS_PRODUCTION: Set to any value when running in production.

Deployment

Create a new tag with the name format release-vx.y.z where x.y.z is a semantic versioning formatted version string e.g. release-v0.1.4

Azure uses the x86_64-unknown-linux-musl platform. Builds are done through a dedicated Docker container that has various C libraries built against musl.

Azure resources defined in main.bicep.

Manual

Requirements:

• Docker e.g. sudo pacman install docker
• Bicep
• Azure CLI
• Azure Functions Core Tools

docker pull clux/muslrust
docker run -v $PWD:/volume --rm -t clux/muslrust cargo build --release
mkdir bin # host.json configured to expect binary here
cp target/x86_64-unknown-linux-musl/release/lamsubs bin/
bicep build ./main.bicep # generates main.json
az login
az deployment group create -f ./main.json -g lamsubs
func azure functionapp publish lamsubs

Automatic

Uses Azure ARM and Login GitHub actions to deploy.

AZURE_CREDENTIALS created as per the service principal instructions.

az ad sp create-for-rbac --name "lamsubs - GitHub" --sdk-auth --role contributor \
    --scopes /subscriptions/SUBSCRIPTIONID/resourceGroups/lamsubs